There’s no doubt Peyton Manning remembers it, too, as his 37-year old body nearly was split in two by what happened on Aug. 17, a Saturday night in Seattle.

Manning uncorked a pass in a 40-10 preseason loss to the Seahawks. Just after his release, the onrushing Wagner was not picked up by rookie running back Montee Ball, and all of Broncos Nation gasped at what happened next.

Wagner, coming forward with his shoulder, made a textbook hit on Manning, delivering a blow into the chest of the quarterback before driving him to the turf with a perfectly legal and lethal takedown. When a teammate thrust his arm out to help Manning up, he waved off the assistance and gathered himself on the ground before slowly getting to his feet.

“I knew it was a good hit,’’ Wagner recalled to The Post on Wednesday from the Seahawks team hotel in Jersey City. “I got him right in the chest. I just wanted him to feel me, let him know Bobby Wagner’s on this field.’’

It was one of the best hits Wagner, a second-year middle linebacker, said he has made in the NFL.

“Good quarterback to do it against,’’ Wagner said, flashing another smile.

The physical confrontation is only one of the challenges Wagner faces as he prepares to match wits with Manning in Super Bowl XLVIII. As the man in the middle of the league’s top-ranked defense, Wagner will see Manning point his way and alert the Broncos that “54’s the Mike’’ on nearly every play, as Wagner almost never comes off the field.

It is Wagner’s job to study every move, every sound, every nuance from Manning, then make the defensive call to put he and the other 10 defenders in the correct places to deal with the record-breaking Broncos offense.

“It’s kind of a chess match,’’ Wagner said. “You got to understand, you got to watch a lot of film, period. But when you’re playing a guy that’s so detailed like Peyton, is you got to watch a lot more film and really understand what they’re trying to do against you and what they’re trying to do to stop you, because he’s going to put his team in a perfect play against your defense, so we got to disguise a little bit. We just got to do our job, run around and play football and we’ll be fine.’’

How can a guy in the NFL for two years, a second-round pick from Utah State, be ready to decipher the trickery and misdirection from perhaps the most cerebral quarterback ever to grace a Super Bowl? Wagner insisted he has studied more for this game than any in his life, but he also insisted he cannot fill his mind with too much information.

“You got to filter it, you watch a lot of film and the stuff you feel like you need you keep and the stuff you feel you don’t need you throw out,’’ Wagner said. “You want to play fast.’’

In many ways Wagner is like so many of his Seattle teammates — young, relatively unheralded outside of the Pacific Northwest and someone who packs a punch. He amassed 140 tackles as a rookie starter and had 119 tackles, five sacks and two interceptions this season. Almost immediately, Wagner gained the trust of the coaching staff and the players with his ability to send out the signals and put people in the correct spot.

“That’s what’s cool about him: He’s only in his second year and he takes control of the huddle, he takes control of the whole defense,’’ defensive end Cliff Avril told The Post. “And doesn’t hesitate, doesn’t have any problems doing it. It’s pretty cool, a young guy out there that can do that. It is unusual but he embraced it and that’s why he’s so good at it.’’

Wagner said he thinks of himself as a director moving around all the talent around him and calls his assignment “a beautiful task.’’ All the attention on Peyton Manning, Wagner says, was expected, because “he’s kind of the face of the league, almost.’’ Now Wagner wants to compete with Manning’s mind games and also put a hit on him just like the one he nailed him with in the preseason.

“If I do it in the Super Bowl,’’ Wagner said, “a lot of people all across the world will remember it.’’